1. Field of the Invention
The present invention relates to an optical scanning device, an image forming apparatus, and an optical scanning method.
2. Description of the Related Art
Typically, regarding electrophotographic image forming apparatuses such as laser printers, facsimileing devices, and digital multifunction peripherals; the advancement in color image formation and the enhancement in operating speed has lead to the prevalence of tandem-type image forming apparatuses that include a plurality of photosensitive drums. In a tandem-type image forming apparatus, each of a plurality of photosensitive drums needs to be independently subjected to light. In that regard, a technology is known with which, as the number of photosensitive drums in a tandem-type image forming apparatus increases, the number of light sources that emit light and that are disposed in an optical scanning device of the tandem-type image forming apparatus can also be increased in proportion to the number of photosensitive drums.
Meanwhile, with an aim of speeding-up the operation of outputting images while standardizing the components, a technology has been developed to perform image formation in a plurality of colors using a single light source (for example, Japanese Patent Application Laid-open No. 2006-284822). More particularly, in a tandem-type image forming apparatus, an opposite scanning optical system is used in which optical paths for scanning the light of a plurality of colors are provided with on the left side and on the right side of a deflecting unit, including such as a polygon motor, that deflects light. With the use of such a plurality of light sources and each being able to emit light of a plurality of colors, the operations can be speeded-up.
However, in a multibeam-type opposite scanning optical system in which a plurality of light sources are installed, the configuration of the optical system or the configuration of the optical components may lead to a misalignment of each beam (light beam) in the sub-scanning direction with respect to a transfer paper sheet. Hence, image formation cannot be performed in an appropriate manner.
Therein, as a method to stabilize the scanning line alignment in the sub-scanning direction, the wire connection of a harness that establishes an image data connection from a control unit to the light sources is nested, or the layouts of control boards on which the light sources are mounted are developed on an individual basis.
However, if a situation occurs when each beam has a different alignment in the sub-scanning direction with respect to the transfer paper sheet, then it becomes difficult to standardize the components even after implementing the technology disclosed in Japanese Patent Application Laid-open No. 2006-284822. Moreover, in order to avoid misalignment in the sub-scanning direction; although it is conceivable to implement a method of changing the image data connection established from a control unit to the light sources, that method is difficult to implement from the perspective of hardware configuration.